Calibre library: When the case of title or author is changed, automatically rename the folders to reflect the new case, even on case insensitive filesystems

src/calibre/library/database2.py

@@ -433,6 +433,28 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                 parent = os.path.dirname(spath)
                 if len(os.listdir(parent)) == 0:
                     self.rmtree(parent, permanent=True)
+        curpath = self.library_path
+        c1, c2 = current_path.split('/'), path.split('/')
+        if not self.is_case_sensitive and len(c1) == len(c2):
+            # On case-insensitive systems, title and author renames that only
+            # change case don't cause any changes to the directories in the file
+            # system. This can lead to having the directory names not match the
+            # title/author, which leads to trouble when libraries are copied to
+            # a case-sensitive system. The following code fixes this by checking
+            # each segment. If they are different because of case, then rename
+            # the segment to some temp file name, then rename it back to the
+            # correct name. Note that the code above correctly handles files in
+            # the directories, so no need to do them here.
+            for oldseg, newseg in zip(c1, c2):
+                if oldseg.lower() == newseg.lower() and oldseg != newseg:
+                    while True:
+                        # need a temp name in the current segment for renames
+                        tempname = os.path.join(curpath, 'TEMP.%f'%time.time())
+                        if not os.path.exists(tempname):
+                            break
+                    os.rename(os.path.join(curpath, oldseg), tempname)
+                    os.rename(tempname, os.path.join(curpath, newseg))
+                curpath = os.path.join(curpath, newseg)
 
     def add_listener(self, listener):
         '''